Kurzfassung

The present work describes the realisation and successful test operation of a 100 kW pilot plant for two-step solar thermo-chemical
water splitting on a solar tower at the Plataforma Solar de Almerı´a, which aims at the demonstration of the feasibility of the process on a
solar tower platform under real conditions. The process applies multi-valent iron based mixed metal oxides as reactive species which are
coated on honeycomb absorbers inside a receiver–reactor. By the introduction of a two-chamber reactor it is possible to run both process
concepts in parallel and thus, the hydrogen production process in a quasi-continuous mode. In summer 2008 an exhaustive thermal qualification
of the pilot plant took place, using uncoated ceramic honeycombs as absorbers. Some main aspects of these tests were the development
and validation of operational and measurement strategy, the gaining of knowledge on the dynamics of the system, in particular
during thermal cycling, the determination of the controllability of the whole system, and the validation of practicability of the control
concept. The thermal tests enabled to improve, to refine and finally to prove the process strategy and showed the feasibility of the control
concept implemented. It could be shown that rapid changeover between the modules is a central benefit for the performance of the
process.
In November of 2008 the absorber was replaced and honeycombs coated with redox material were inserted. This allowed carrying out
tests of hydrogen production by water splitting. Several hydrogen production cycles and metal oxide reduction cycles could be run without
problems. Significant concentrations of hydrogen were produced with a conversion of steam of up to 30%.

Dokumentart:

Zeitschriftenbeitrag

Titel:

Test operation of a 100 kW pilot plant for solar hydrogen production from water on a solar tower